Fuel pump replacement?

[DohertyCM]

I have a 1974 911 CIS 2.7. Is there a possibility of replacing the fuel pump with a new improved aftermarket fuel pump. What are the spec's I should look for if this is possible.

Chris

[bigchillcar]

chris,
what is the justification for the need for a different pump? a working original should be satisfactory if you're staying with the stock cis motor otherwise..
ryan

[DohertyCM]

I dont know. Just thinking with my hands. I thought new technology in the car would improve reliability, performance and peace of mind.

Am I wrong in my thinking.

[Nitrometano]

The only important thing about the fuel pump is the capacity to flow gallons per hour (gph) and the constant pressure or the pressure that can make for the specific engine needs. Most of the fuel pumps have up to 20% more capacity for fuel supply than the engine needs.

[Grady Clay]

Chris,

The best thing you can do is to relocate the pump from the
rear to the front cross member like the ’69-70 and the ’76
and later. Of course a new fuel pump (OEM or later) never
hurts but is only necessary when close to failure and/or noisy.
Here is the ’76 installation.
“
"
© Dr. Ing. h.c. F. Porsche A.G.

Best,
Grady

[RoninLB]

The Bosch CIS fuel pump is a mechanically great unit imo. I still use it.

[Jim Sims]

There are good aftermarket electric fuel pumps that can be installed in place of the Bosch pumps. They are slightly smaller and lighter that the OEM units and generally can be had with the correct pressure/flow rate specifications (there is one that is a perfect match for a 1974 CIS system). The vendors typically have a selection of fuel connection fittings that allow them to be readily installed in 911's in place of the Bosch units. The only apparent advantage other than the slight reduction in size and weight is that they are about 1/3 to 1/2 the cost of the Porsche Bosch units. If your present OEM unit is working correctly I'd leave it alone as you won't gain much by changing it as long as it is putting fuel out per it's design specifications. That being said low fuel pump pressure and flow rate will reduce power output in a CIS car. I'm still running around with my 29-year old OEM unit but I also carry one of the aftermarket fuel pumps as a spare.

[Fidalgo911S]

Jim, do you have the name of the aftermarket pump? I've still got the original in my '74 S and I'm just waiting for the day it gives up the ghost. I wouldn't mind saving a few bucks by not having to purchase the Bosch unit when that happens.

[Jim Sims]

Walbro, model: GSL392

[Jim Sims]

[Charlie V]

Pelican sells a ton of good stuff.

I replaced my pump with the a Bosch pump that I picked up at a local euro car parts supplier. This one was for a late 70's VW Rabbit. This is the best part.....50% of the cost of the Prosche part and it is the same damn pump - exact same Bosch part number.

With the extra $ I purchased more things from Pelican.

[Fidalgo911S]

Thanks Jim.